1. Field of the Invention
The invention relates to a moving picture decoding method, a moving picture decoding program, a moving picture decoding apparatus, a moving picture encoding method, a moving picture encoding program, and a moving picture encoding apparatus.
2. Related Background of the Invention
In the draft standard of the H.264 extension system, which is a moving picture encoding system, each of pictures provided for the left-view (left-view picture) and for the right-view (right-view picture) in a stereo picture can be encoded as either an odd line field or an even line field of an interlaced signal (an interlaced scanned picture). Further, a stereo video field message (stereo information) is specified as identification information indicating whether or not encoded moving picture data relates to a stereo picture. By referring to the data of the stereo video field message included in the encoded moving picture data, a decoder which decodes moving picture data can recognize whether each decoded field is a left-view or right-view picture of a stereo picture (for example, refer to Text of ISO/IEC 14496-10: 2003/FPDAM1 (AVC Professional Extensions), March 2004). Here, “a field” denotes a picture forming a moving picture, indicating a picture formed by odd scanning lines (odd line field), or a picture formed by even scanning lines (even line field) in a frame constituting a whole picture.
On the other hand, in the H.264 system, relative position among each output time of decoded picture (the term “picture” is a general term for a frame, a field, and a pair of two fields (hereinafter, referred to as a two-field pair)), which is a unit of decoding of a moving picture, is specified by information called Picture Order Count (POC), and the POCs of Top field and Bottom field are specified as Top POC and Bottom POC, respectively. When Top field and Bottom field are handled as components of a frame or a two-field pair (the same frame number is assigned to the two fields), a smaller value of Top POC and Bottom POC is specified as the POC. Therefore, the two fields have the same POC value. When Top field and Bottom field are handled as individually different fields (different frame numbers are assigned to the two fields), the POC values of the two fields are different. This information indicates relative position among each pictures in the temporal direction and is used, for example, in a prediction processing between pictures. Further, in the H.264 system, encoding of a time stamp of a decoded picture is specified. In a picture timing message including information of the above-mentioned time stamp in the H.264 system, it is possible to specify the number of time stamps to be encoded (one for a frame, one for a field, two for a two-field pair, etc.) using picture type information (picture_struct). In some cases, time information may be defined by system data integrating video data and audio data.